Notes

Taxonomic Notes

Limaya belongs to the Diamesinae tribe Heptagiini – the tribe is austral and well-defined in all stages. However it is not possible yet to distinguish the larvae to genus level with certainty: too few have been reared and it is unclear which characters are reliable. Although the ‘distinctive’ collar (occipital margin of the head) may be a feature only of final instar larvae, in Limaya a 3rd instar larva shares the collar of its conspecific 4th .

Brundin (1966) reported:
Head capsule as in Maoridiamesa (q.v.) and Reissmesa (q.v) with dorsolateral emargination on each side of occipital margin. As in Maoridiamesa the posterior pseudopods have many hooks; also similar are the flattened, lancet-shaped sensillar labral S I-III. The following features of the Limaya larva are distinctive:

(1) Chaetotaxy of the larval body stronger developed than in the other genera of the tribe, the dorsal setae of the middle abdominal segments being about 1/4 as long as the diameter of the body.

(2) SI seta as in Paraheptagyia in a mesal position anterior to SII-III, strongly developed and inserting on large sockets laterally provided with two large, pointed projections.

(3) The 5 "teeth" of the epipharyngeal comb strongly flattened and very broadly rounded at tip; because of their great width they are not arranged in a single row as usual, but like roofing-tiles, the upper row consisting of two lamellae, the middle row of a single, extremely wide lamella, and the lower row of two, comparatively narrow lamellae.

(4) Mentum with a very broad middle tooth and only 5 lateral teeth on each side.

(5) Head capsule more strongly arched than in related genera, with less marked dorsolateral incisions compared to Reissmesa.

A newly-discovered larva otherwise identical with Brundin’s description does not show the precise structure of the pecten epipharyngis described above, but certainly the middle three scales overlap the outer. Further, the body setae are not as long as Brundin indicated.

Ecological Notes

The immature stages of Limaya longitarsis, the only know species, are found in fast-flowing Andean streams in Chile and Argentina between 40˚ and 41˚ S.